Health services research has the potential to transform global health care through the study of the relationship between a population's health and its resources. Accordingly, in the US there are mounting efforts to monitor and improve quality of patient care and safety. Patient Safety Indicators (PSIs) were developed by the Agency for Healthcare Research and Quality (AHRQ) as a set of references to assess potential in-hospital adverse events. Surgical subspecialties offer an ideal setting to study PSIs, as processes and outcomes are closely related. The goal of this proposal is to utilize resources at Stanford University for Tina Hernandez- Boussard, Ph.D., MPH to continue to develop her career as an independent health services researcher and to establish national trends in health care quality in surgical subspecialties, identify areas of priority, and determine predictors of quality of care using administrative data. The national quality of inpatient health care services in surgical subspecialties has not been assessed. Particularly lacking are rigorous evaluations of trends in adverse events by specialty. As certain surgical subspecialties account for a disproportionate share of adverse outcomes, the examination of PSIs in surgical subspecialties will identify areas with potential large impacts on public health. Accordingly, the focus of this proposal is on quality improvement of the US healthcare system through extensive evaluation of PSIs in surgical subspecialties and identification of areas where quality efforts can be focused to produce the greatest public health impact. The proposed career development and research plan couples new methodologies with current quality indicators using administrative data to assess patient safety in surgical subspecialties at the national level; evaluates time trend analyses in PSIs in surgical subspecialties; and determines patient, physician, and organizational predictors of quality of care in surgical subspecialties. This research on the relationship between a population's health and its resources has the potential to save a substantial number of lives in the next decade. PSIs were developed to study this relationship and identify areas where improvement of adverse outcomes is achievable. Accomplishing the specific aims outlined in this proposal will provide a foundation for hospitals to focus their surgical quality improvement efforts (Aim #1), hospitals will be able to rank their overall quality improvement performance and identify opportunities for improvement (Aim #2) and models will suggest areas in surgery that are predictive of poor quality of care and therefore merit focus (Aim #3). These development and research plans address several priority issues on the AHRQ research agenda including patient safety and strengthening quality measurement to reduce complication rates and potentially improve health care quality in the next decade.